POWER LOSS (mW) LTC3631 High Efficiency, High Voltage 100mA Synchronous Step-Down Converter FeaT DescripT n Wide Input Voltage Range: Operation from 4.5V to 45V The LTC 3631 is a high voltage, high efficiency step-down n Overvoltage Lockout Provides Protection Up to 60V DC/DC converter with internal high side and synchronous n Internal High Side and Low Side Power Switches power switches that draws only 12A typical DC supply n No Compensation Required current at no load while maintaining output voltage n 100mA Output Current regulation. n Low Dropout Operation: 100% Duty Cycle The LTC3631 can supply up to 100mA load current and n Low Quiescent Current: 12A features a programmable peak current limit that provides n 0.8V 1% Feedback Voltage Reference a simple method for optimizing efficiency in lower current n Adjustable Peak Current Limit applications. The LTC3631s combination of Burst Mode n Internal and External Soft-Start operation, integrated power switches, low quiescent cur- n Precise RUN Pin Threshold with Adjustable rent, and programmable peak current limit provides high Hysteresis efficiency over a broad range of load currents. n 3.3V, 5V and Adjustable Output Versions n With its wide 4.5V to 45V input range and internal overvolt- Only Three External Components Required for Fixed age monitor capable of protecting the part from 60V surges, Output Versions n the LTC3631 is a robust converter suited for regulating a Low Profile (0.75mm) 3mm 3mm DFN and wide variety of power sources. Additionally, the LTC3631 Thermally-Enhanced MS8E Packages includes a precise run threshold and a soft-start feature to guarantee that power system start-up is well-controlled Ta in any environment. n 4mA to 20mA Current Loops The LTC3631 is available in the thermally enhanced n Industrial Control Supplies 3mm 3mm DFN and MS8E packages. n Distributed Power Systems L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n Portable Instruments and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the n property of their respective owners. Battery-Operated Devices n Automotive Power Systems Efficiency and Power Loss vs Load Current Typical Ta 100 EFFICIENCY 90 1000 5V, 100mA Step-Down Converter 80 100H V OUT V 70 100 IN V SW 5V IN 5V TO 45V 100mA LTC3631-5 2.2F 10F 60 RUN V POWER LOSS OUT 50 10 HYST SS I SET 40 GND 30 1 V = 12V IN 3631 TA01a V = 36V IN 20 0.1 1 10 100 LOAD CURRENT (mA) 3631 TA01b 3631fe 1 For more information www.linear.com/LTC3631 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3631 Ta e MaxiMMu Tar (Note 1) V Supply Voltage ..................................... 0.3V to 60V Operating Junction Temperature Range IN SW Voltage (DC) ........................... 0.3V to (V + 0.3V) (Note 2) .................................................. 40C to 125C IN RUN Voltage .............................................. 0.3V to 60V Storage Temperature Range ................... 65C to 150C HYST, I , SS Voltages ............................... 0.3V to 6V Lead Temperature (Soldering, 10 sec) SET V ............................................................... 0.3V to 6V MS8E ................................................................ 300C FB V (Fixed Output Versions) ....................... 0.3V to 6V OUT in p Fc T TOP VIEW TOP VIEW SW 1 8 GND SW 1 8 GND V 2 7 HYST IN 9 V 2 9 7 HYST IN GND GND I 3 6 V /V I V /V SET OUT FB 3 6 SET OUT FB SS 4 5 RUN SS RUN 4 5 MS8E PACKAGE 8-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 40C/W, = 5-10C/W JMAX JA JC 8-LEAD (3mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 43C/W, = 3C/W JMAX JA JC EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB Der inFMTa LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3631EMS8E PBF LTC3631EMS8E TRPBF LTFDT 8-Lead Plastic MSOP 40C to 125C LTC3631EMS8E-3.3 PBF LTC3631EMS8E-3.3 TRPBF LTFFP 8-Lead Plastic MSOP 40C to 125C LTC3631EMS8E-5 PBF LTC3631EMS8E-5 TRPBF LTFFR 8-Lead Plastic MSOP 40C to 125C LTC3631IMS8E PBF LTC3631IMS8E TRPBF LTFDT 8-Lead Plastic MSOP 40C to 125C LTC3631IMS8E-3.3 PBF LTC3631IMS8E-3.3 TRPBF LTFFP 8-Lead Plastic MSOP 40C to 125C LTC3631IMS8E-5 PBF LTC3631IMS8E-5 TRPBF LTFFR 8-Lead Plastic MSOP 40C to 125C LTC3631EDD PBF LTC3631EDD TRPBF LFDV 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3631EDD-3.3 PBF LTC3631EDD-3.3 TRPBF LFFN 40C to 125C 8-Lead (3mm 3mm) Plastic DFN LTC3631EDD-5 PBF LTC3631EDD-5 TRPBF LFFQ 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3631IDD PBF LTC3631IDD TRPBF LFDV 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3631IDD-3.3 PBF LTC3631IDD-3.3 TRPBF LFFN 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3631IDD-5 PBF LTC3631IDD-5 TRPBF LFFQ 40C to 125C 8-Lead (3mm 3mm) Plastic DFN Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: